Potosi is a village in Grant County, Wisconsin, United States. The population was 711 at the 2000 census. The village is in the Town of Potosi.
Known as "the Catfish Capital of Wisconsin," the village holds an annual Catfish Festival and Fireman's Fish Fry, typically on the 2nd weekend of August. The event includes a truck and tractor pull, beanbag and a euchre tournament, fireworks, live music, a parade, and the fish fry. The National Brewery Museum and Library opened in the village on the site of the Potosi Brewery in 2008. The museum features historic beer and brewing memorabilia, including signs, advertisements, bottles, cans, and miscellaneous paraphernalia.
Local road signs herald Potosi's Main Street as "the longest Main Street in the world." A newspaper article traces the claim to a 1950s item in Ripley's Believe It Or Not which made the more qualified statement that it is the longest Main Street without a cross street. Current maps show a three-mile stretch, with numerous streets--including one named "Cross Street"--that drain into it and end, forming T-shaped intersections, but no street that continues across it. The stretch is divided into two portions each with a distinct street name: North Main Street and South Main Street.